Wireless Messaging System

ABSTRACT

Messages are routed via a cellular communications network to multiple cellular communications receivers configured for answering calls placed to a common subscriber number, such that a message originated with a single cellular call may reach multiple recipients. The geographic area of message distribution may be controlled by selectively enabling different cell sites for calling particular subscriber numbers. The cellular receivers may have message storage capabilities for subsequent replay of received messages. Message storage may be provided by downloading messages to a conventional telephone answering device also connected for landline telephone call answering, thereby adding received cellular messages to recorded landline telephone messages.

This application is a Continuation of application Ser. No. 10/968,422filed Oct. 18, 2004 which claims priority to the filing date ofProvisional Application 60/496,945 filed Aug. 18, 2003

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to the field of cellular wirelesscommunications, and more particularly relates to one way wirelessmessaging using cellular communications networks.

2. State of the Prior Art

Cellular wireless communication systems are widely deployed and used formobile telephone and other communications. Current use typicallyinvolves communications between individual subscribers each equippedwith a handheld cellular telephone unit. The mobile units are eachassigned unique telephone numbers and cellular communications aretypically private between parties known to the cellular network.

The mobile handsets communicate via a cellular network which includestransponder cellsites each having a limited area of coverage and locatedso as to provide contiguous areas or cells of radio coverage over alarger area of service. The mobile handsets periodically transmit anidentification signal which is used to locate the handset within thecoverage area of one or more cellsites. The cellsites in turn arenetworked by trunk lines and are managed by a central control office.The location of active handsets received by all of the cellsites isknown to the digital control system, so that a call placed to aparticular wireless handset is placed, either from another mobilehandset or from a conventional landline telephone, can be directed to acellsite within radio range of the target handset. Two waycommunication, by landline for example, can then be established from thecentral control office to the appropriate cellsite, and the linkcompleted by two-way radio communication between the cellsite and thehandset. A detailed description of the operation of cellularcommunication networks is not necessary here as the topic is relativelycomplex and the information is available from publicly accessiblesources.

Communications using such cellular networks are directed to specificsubscribers, that is, to particular telephone numbers in a cellulartelephone network. While messaging services exist for directingcommunications such as text messages to multiple recipients, each of themessage recipients is also specified to the cellular network and knownto the sender.

SUMMARY OF THE INVENTION

This invention provides a wireless messaging system which in a presentlypreferred embodiment makes use of a cellular communications network suchincluding a number of cellsites for routing wireless messages tosubscribers located within range of one or more of the cellsites. Thecellular communications network may be of the type which is normallyconfigured for monitoring the presence and location of individual activemobile handsets relative to different cellsites, such that messages orcalls addressed to any one mobile number can be routed through anappropriate cellsite within range of the handset corresponding to thatmobile number. For purposes of this invention, however, the cellularnetwork is configured to operate without monitoring or verifying thepresence of mobile handsets corresponding to mobile numbers assigned toa special category of subscriber here referred to as a broadcastsubscriber. The broadcast subscriber is assigned a broadcast numberwhich may be a particular mobile telephone number. Calls placed to abroadcast number are transmitted by one or more broadcasting cellsiteswithout verifying the presence of a mobile handset corresponding to thatbroadcast number in the area covered by those one or more cellsites. Thebroadcasting cellsites are selected by the broadcast subscriber, forexample, as part of a subscription agreement with the cellular networkservice provider. The one-way message broadcasting aspect of thecellular network may coexist with conventional two-way mobilecommunications by the network.

A number of cellular communications receivers are installed at recipientsites located within range of the broadcast cellsites. Each receiver isconfigured to accept calls routed to a broadcast number. Multiple suchreceivers may be configured to accept calls addressed to a samebroadcast number through the broadcast cellsite or cellsites, such thatmultiple receivers may receive a call placed to a single broadcastnumber. A particular broadcast call or message may be broadcast throughmore than one cellsite so as to cover a wider geographic area ofreception. Also, a broadcast call may be stored by the cellular networkprovider for subsequent broadcast through one or more cellsites, forexample, during off-peak times of network usage.

In typical cellular communications networks the cellsite initiates atwo-way call or communication with a mobile handset by assigningavailable frequencies or channels for the communication session,including a receive frequency and a transmit frequency for the mobilehandset. The cellular receivers used in the preferred embodiment of thepresent invention lack transmission capability, so that no assignment oftransmit frequency is needed. However, the receivers are preferablyresponsive to communications channel assignment control signaltransmitted by the broadcasting cellsite, such that the receiverswitches to a receive frequency assigned for the particular broadcast bythe broadcasting cellsite, so that the cellular broadcast can be madeover a frequency then available to the broadcasting cellsite. Thisassignment of receive frequencies can be made in the conventional mannercurrently employed with conventional two way mobile telephone handsets,for example.

The cellular receivers preferably have message storage capabilities,such as digital storage, for subsequent replay of received messages.

In one embodiment of the invention the cellular receivers are standalone units with built in message playback capability, including forexample, audio playback of voice messages, and for this purpose may havean audio amplifier and loudspeaker as part of the receiver unit.

In another embodiment of the invention the cellular receivers cooperatewith a conventional telephone answering device of the type commerciallyavailable for answering calls to landline telephones and storing voicemessages for subsequent replay. In this embodiment the cellularreceivers may be configured for receiving operating power from alandline telephone jack, and may be also configured for downloadingstored cellular messages to the conventional telephone answering devicefor subsequent replay by the conventional answering device. In thislatter embodiment, the cellular receivers may be built as a single unittogether with the landline telephone answering device, for example, in acommon housing.

In still other embodiments of the invention the cellular receivers maybe preprogrammed for answering to one or more broadcast numbers. Thecellular receivers may be reprogrammable by end users for answering todifferent or additional broadcast numbers.

These and other improvements, features and benefits will be betterunderstood by reference to the following detailed description of thepreferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts in schematic form a group of cellsites comprising part ofa larger cellular communications network and a number of cellularreceivers located in some of the cell areas of coverage provided by thecellsites; and

FIG. 2 is a perspective view of a cellular receiver unit according tothis invention connected between a wall mounted telephone jack and atypical telephone answering device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 depicts in schematic form a group of cellsites 12 comprising partof a larger cellular communications network 10 and a number of cellularreceivers 14 located in some of the cell areas 16 of coverage providedby the cellsites 12.

The cellular communications network 10 and cellsites 12 are configuredwith hardware and software operative for routing wireless calls andmessages to mobile subscribers located within the area of coverage ofthe network and providing two-way communications with cellular handsets20 carried by the mobile subscribers. The area of service provided bynetwork 10 is divided into contiguous cells 16. Coverage for each cell16 is provided by a group of corresponding cellsites 12. For example,cellsites 12 a,12 b and 12 c each include radio transmitters withantennas which have a generally elliptical radiation pattern suggestedby ellipses 12′a, 12′b and 12′c respectively, such that these threecellsites together cover the area of one cell 16 contained generallybetween the cellsites. A conventional cellular communications network 10is normally configured for monitoring the presence and location ofconventional two-way mobile handsets 20 relative to different cellsites12, such that messages or calls addressed to mobile numbers assigned tothe two-way handsets can be routed by a mobile telecommunicationsswitching office 26 through trunk lines 28 to an appropriate cellsite 12within radio communications range of the mobile handset 20 correspondingto that mobile number.

For purposes of the messaging system of this invention, cellularcommunications receivers 22 are located within receiving range of thebroadcast cellsites 12. Each receiver 22 is configured to accept callsrouted to a broadcast number. However, in the presently preferredembodiment the cellular receivers 22 do not register with the cellularnetwork by identifying themselves to any cellsites 12, and receivers 22have no transmit capability at all so that many receivers can operate inone cell 16 without interference or conflict. For purposes of thisinvention, a subset of mobile numbers, which may be mobile telephonenumbers reserved for broadcast use, is reserved for assignment to aspecial category of subscriber, which is here referred to as a broadcastsubscriber. The cellular network 10 is configured through appropriatemodification of either hardware, software or both, to make calls to anyof the reserved broadcast numbers without testing for the presence ofmobile receiving units pertaining to the broadcast numbers. The cellularreceivers 22 are each configured to accept calls placed to one or moreof the mobile numbers. Multiple broadcast subscribers are assigneddifferent broadcast numbers. Each broadcast subscriber is able to sendmessages to a group of recipients, each recipient being equipped with acellular receiver 22 programmed to answer calls placed to that broadcastsubscriber's broadcast number. Different broadcast subscribers can reachdifferent groups of broadcast recipients.

Calls placed to a broadcast number from a conventional telephone, eitherlandline or cellular, are transmitted by one or more cellsites 12without verifying the presence of a mobile handset 20 or receiver 22corresponding to that broadcast number in the cells 16 covered by thosecellsites 12. When operating in this broadcasting mode the cellsites 12are referred to as broadcasting cellsites, although physically they maybe the same cellsites 12. The cellsites 12 can operate in bothconventional two-way private communication with individual subscribers,or broadcast mode for one-way transmission of messages from one callerto groups of recipients whose identity or presence is not necessarilyknown or detectable to the cellular network 10. Consequently, theone-way message broadcasting aspect of the cellular network may coexistwith conventional two-way mobile communications on a given network 10.

Multiple such receivers 22 may be configured to accept calls addressedto a same broadcast number by any broadcast cellsite 12, such thatmultiple receivers 22 in the same cell 16 may receive a call placed to asingle broadcast number. A particular broadcast call or message may bebroadcast by multiple cellsites 12 to cover multiple cells 16, eachcontaining multiple receivers 22 programmed to answer to the samebroadcast number, for a wider geographic area of message reception.Also, broadcast calls may be stored by the cellular network system 10for subsequent broadcast through one or more cellsites 12, for example,during off-peak times of network usage or to take advantage of momentaryfrequency availability.

The number of cells 16 covered by a cellular broadcast may be determinedby the requirements of the broadcast subscriber, for example, as part ofa subscription agreement with the cellular network service provider. Thebroadcasting cellsites 12 may be chosen, for example, to cover ageographic area populated by a given group having a common interest orbelonging to a common organization such as a school or church. In suchcase the broadcast subscriber may be the school or church which isinterested in efficiently communicating with its student body orcongregants, respectively. In such organizations a large proportion ofthe group typically resides in general vicinity to the school or church.A cellular message may be delivered to all or most members of the group,when each is equipped with a cellular communications receiver 22, with asingle telephone call placed to the broadcast number assigned to thatbroadcast subscriber by the cellular network service provider, from anytelephone, whether landline or cellular, from anywhere in the worldwhere phone service is available. The number of cellsites accessible bythe broadcast subscriber may be a single cellsite for limited localcoverage or may include many cellsites if wider area message delivery isneeded.

In typical cellular communications networks 10 the cellsite 12 sets-up atwo-way call or communication session with a mobile handset 20 byassigning available frequencies or channels for the communicationsession, including a receive frequency and a transmit frequency for themobile handset 20. The cellular receivers 22 used in the preferredembodiment of the present invention lack transmission capability, sothat no assignment of transmit frequency is needed. However, thereceivers 22 may be responsive to communications channel assignmentcontrol signals transmitted by the broadcasting cellsites 12, such thatthe receiver 22 switches to a receive frequency assigned for theparticular broadcast by the broadcasting cellsite 12, so that thecellular broadcast can be made over a frequency then available to thebroadcasting cellsite 12. This assignment of receive frequencies by thecellsite 12 can be made in the conventional manner currently employedwith conventional two way mobile telephone handsets 22, for example.

The cellular receivers preferably have message storage capabilities,such as digital storage, for subsequent replay of received messages.

In one embodiment of the invention the cellular receivers 22 are standalone units with built in message playback capability, including forexample, audio playback of voice messages, and for this purpose may havean audio amplifier and loudspeaker as part of the receiver unit.

In another embodiment of the invention, illustrated in FIG. 2, thecellular receivers 22 is a unit equipped with a cellular antenna 42 andinterconnected with a telephone answering device 30 of the typecommercially available for answering calls made to landline telephonesand storing voice messages for subsequent replay. In the illustratedexample, answering device 30 includes a wireless handset 38. In thisembodiment the cellular receivers 22 may be configured for receivingoperating power from a landline telephone jack 32. Receiver 22 has amessage storage capability, such as a digital storage, for storingreceiver cellular broadcast messages. The receiver 22 is programmed toperiodically download the cellular messages initially stored in receiver22 via cord 40 for storage on answering device 30, for subsequent replayby the answering device 30. In such a system, messages received over thetelephone land line 34 and the cellular messages received by thecellular receiver 22 may both be replayed in response to the messagereplay function of the answering device 30. In a variant of this latterembodiment, the cellular receivers 22 may be built as a single unittogether with the landline telephone answering device 30, for example,in a common housing containing the necessary power supplies for bothcellular receiver and answering device.

The cellular receiver 22 may be provided with an interface to theconventional answering device 30. The interface tests for availabilityof a dial tone from jack 32 to ensure that no landline telephone call isin progress that will be interrupted by offloading of the storedmessage. The interface may also take the landline telephone line“off-hook” while actuating the answering device 30 and offloadingmessages from cellular receiver 22. In FIG. 2, the receiver 22 includesappropriate switching for normally connecting answering device 30 tophone jack 32 and bypassing the receiver 22, and temporarilyinterrupting this connection for downloading stored cellular messagesfrom receiver 22 to answering device 30. The answering device 30 neednot differentiate between messages conventionally received via thetelephone line 34 and messages received via the cellular receiver 22.Both types of messages are heard in the usual manner by activating the“play messages” function of the recipient's answering device 30. In thisconfiguration this system operates with commercially available answeringmachines 30 of any brand or design without special setup or modificationother than the connection of the cellular radio receiver 22 to theanswering machine 30, normally between the recipient's incomingtelephone line 34 and the answering machine 30, as shown.

The cellular receivers 22 may be preprogrammed for answering to one ormore broadcast numbers, such that a given cellular receiver 22 may beused to receive messages from various broadcast subscribers representingdifferent organizations of interest to the particular recipient. Thecellular receivers 22 may be reprogrammable by end users for answeringcellular calls placed to different or additional broadcast numbers, andfor this purpose may have a numerical keypad or other suitable inputdevice.

In yet another embodiment of the invention, the cellular receivers 22are modified to include a transmitter section capable of reporting thepresence of the receiver to a broadcasting cellsite 12 and registeringwith the network 10 in a manner similar to the reporting capability ofexisting two-way mobile telephones. In this embodiment the cellularreceivers are registered with the cellular service provider in manneranalogous to the registration of two-way mobile telephone handsets,although multiple cellular receivers are still configured toautomatically receive calls or messages addressed to a given broadcastnumber. The broadcasting cellsites 12 in this embodiment can track thecellular receivers present in each cell 16, for example, for census orbilling purposes.

In still other embodiments of the invention, a two-way cellulartelephone unit such as a mobile handset 20 is modified so as toincorporate the functions of cellular receivers 22 of this inventionwithout prejudice to its normal two-way functionality. For this purposea separate cellular broadcast receiver 22 subsystem such as describedabove is included in the housing of the two-way cellular telephone unit20 and configured to function independently of the two-way subsystem.Alternatively, the cellular receiver section of a two-way cellulartelephone unit 22 is modified to also operate in a one-way messagingmode by automatically responding to cellular calls placed to apreprogrammed broadcast number.

The cellular telephone network is a convenient means for one-waytransmission of messages. However, this invention is not limited tocellular networks and other radio frequency communication networksincluding simple radio frequency transmitters operating at anyconvenient frequency can be also employed for message transmission tothe multiple receivers 22.

Implementation of the various embodiments disclosed above can beaccomplished by those having an ordinary level of skill in cellularcommunications network engineering or related technologies, based uponthe foregoing description without an undue degree of experimentation.

Particular embodiments of the invention have been described for purposesof clarity and example. It will be understood, however, that manychanges, modifications and substitutions to the described embodimentswill be apparent to those having only ordinary skill in the art withoutthereby departing from the scope of the invention as defined in thefollowing claims.

1. A cellular wireless messaging system comprising: a cellular radiocommunications network including a plurality of cellsites for routingcellular calls addressed to one or more subscriber numbers within ageographic area of coverage of said cellsites, wherein presence andlocation of individual active cellular handsets is monitored relative todifferent ones of said cellsites such that a call directed to aparticular cellular telephone number can be routed through anappropriate one of said cellsites within range of a handsetcorresponding to said particular cellular telephone number; and aplurality of cellular radio communications receivers distributed withinsaid geographic area of coverage, each capable of registering itspresence with one or more of said cellsites and each configured toaccept cellular calls addressed by said cellsites to the same one ofsaid cellular telephone numbers within said subset such that multiple ofsaid cellular radio receivers may each receive a particular cellularcall addressed to a single cellular telephone number within said subset,thereby enabling a cellular telephone call to be sent to multiplecellular receivers by originating a single cellular call while alsotracking the presence of said cellular radio communications receiverspresent for census or billing purposes.
 2. The cellular wirelessmessaging system of claim 1 wherein each of said cellular radiocommunications receivers is operative for automatically receiving callsor messages placed to one or more telephone numbers in said subset. 3.The cellular wireless messaging system of claim 1 wherein said cellularradio communications receivers comprise a two-way cellular mobiletelephone handset modified to incorporate the functions of claim 1without prejudice to its normal two-way functionality.
 4. The cellularwireless messaging system of claim 1 wherein each of said cellular radiocommunications receivers is included in a housing of a two-way mobilecellular telephone handset.
 5. The cellular wireless messaging system ofclaim 4 wherein said cellular radio communications receiver included insaid housing is configured to function independently of said two-waymobile cellular telephone handset.
 6. The cellular wireless messagingsystem of claim 1 wherein each of said cellular radio communicationsreceivers is a section of a two-way mobile cellular telephone handsetconfigured to also operate in a one-way messaging mode by automaticallyresponding to cellular calls placed to a preprogrammed broadcast numberin said subset.
 7. The system of claim 1 wherein each of said cellularradio communications receivers is user programmable for answeringcellular calls placed to one or more different ones of said cellulartelephone numbers in said subset.
 8. A cellular wireless messagingsystem comprising: a cellular radio communications network including aplurality of cellsites for routing cellular calls addressed to one ormore subscriber numbers within a geographic area of coverage of saidcellsites, wherein presence and location of individual active cellularhandsets is monitored relative to different ones of said cellsites suchthat a call directed to a particular cellular telephone number can berouted through an appropriate one of said cellsites within range of ahandset corresponding to said particular cellular telephone number; anda plurality of cellular radio communications receivers distributedwithin said geographic area of coverage, each configured toautomatically receive cellular calls addressed by said cellsites to thesame one of said cellular telephone numbers within said subset such thatmultiple of said cellular radio receivers may each receive a particularcellular call addressed to a single cellular telephone number withinsaid subset, thereby enabling a cellular telephone call to be sent tomultiple cellular receivers by originating a single cellular call, eachof said cellular radio communications receivers having digital voicemessage storage capabilities for subsequent replay of received messages.9. The cellular wireless messaging system of claim 8 wherein each ofsaid cellular radio communications receivers is capable of registeringits presence with one or more of said cellsites.
 10. The cellularwireless messaging system of claim 8 wherein said cellular radiocommunications receivers comprise a two-way cellular mobile telephonehandset modified to incorporate the functions of claim 1 withoutprejudice to its normal two-way functionality.
 11. The cellular wirelessmessaging system of claim 8 wherein each of said cellular radiocommunications receivers is included in a housing of a two-way mobilecellular telephone handset.
 12. The cellular wireless messaging systemof claim 11 wherein said cellular radio communications receiver includedin said housing is configured to function independently of said two-waymobile cellular telephone handset.
 13. The cellular wireless messagingsystem of claim 8 wherein each of said cellular radio communicationsreceivers is a section of a two-way mobile cellular telephone handsetconfigured to also operate in a one-way messaging mode by automaticallyresponding to cellular calls placed to a preprogrammed broadcast numberin said subset.
 14. The system of claim 8 wherein each of said cellularradio communications receivers is user programmable for answeringcellular calls placed to one or more different ones of said cellulartelephone numbers in said subset.
 15. A cellular wireless messagingsystem comprising: a cellular radio communications network including aplurality of cellsites for routing cellular calls addressed to one ormore subscriber numbers within a geographic area of coverage of saidcellsites, wherein presence and location of individual active cellularhandsets is monitored relative to different ones of said cellsites suchthat a call directed to a particular cellular telephone number can berouted through an appropriate one of said cellsites within range of ahandset corresponding to said particular cellular telephone number; anda plurality of cellular radio communications receivers distributedwithin said geographic area of coverage, each configured to acceptcellular calls addressed by said cellsites to the same one of saidcellular telephone numbers within said subset such that multiple of saidcellular radio receivers may each receive a particular cellular calladdressed to a single cellular telephone number within said subset,thereby enabling a cellular telephone call to be sent to multiplecellular receivers by originating a single cellular call; each of saidcellular radio communications receivers being user programmable foranswering cellular calls placed to one or more different ones of saidcellular telephone numbers in said subset.
 16. The system of claim 15wherein said cellular communications network is configured forforwarding a call originated to a single cellular telephone numberthrough more than one of said cellsites such that multiple ones of saidreceivers in range of different ones of said cellsites may be addressedby a call to said single cellular telephone number.
 17. The system ofclaim 15 wherein said cellular communications receivers are responsiveto communications channel assignment control signals transmitted by saidcellsites.
 18. The system of claim 15 wherein said receivers areconfigured for downloading stored voice messages to a conventionaltelephone answering device of the type for answering calls made tolandline telephones and storing voice messages for subsequent replay.